package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private UserServiceImpl userService;

    @Override
    public Result follow(Long followUserId,Boolean isFollow) {

        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        String key = "follows:"+userId;

        //判断到底是关注还是取关
        if (isFollow){

            //新增，关注数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = this.save(follow);
            if (isSuccess){
                //把关注用户的id，放入redis的set集合，sadd userId followUserId
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else{
           boolean isSuccess = remove(new QueryWrapper<Follow>()
            .eq("user_id", userId)
                    .eq("follow_user_id",followUserId));
          if (isSuccess) {
              //把关注用户的id从redis集合中移除
              stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
          }
        }
        return Result.ok();
    }

    //查询是否关注
    @Override
    public Result isfollow(Long followUserId) {

        //获取登陆用户
        Long userId = UserHolder.getUser().getId();
        //查询是否关注
       Integer count = query().eq("user_id", userId)
                .eq("follow_user_id",followUserId).count();

        return Result.ok(count>0);
    }

    @Override
    public Result followCommons(Long id) {

        //获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key = "follows:"+userId;

        //2.求交集
        String key2 = "follows:"+id;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key,key2);
        if (intersect == null || intersect.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }

        //解析id集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
       //查询用户
        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user,UserDTO.class))
                .collect(Collectors.toList());

        return Result.ok(users);
    }
}
